Chronically ill patients in the hospital, and post-discharge, are known to be at a high risk for poor outcomes such as adverse drug reactions, decreased functioning and preventable re-hospitalization. [1-3]. Good care coordination has been shown to decreases costs and improves patient outcomes [4-9]. Staff nurse care coordination is a critical nursing process impacting safety and quality outcomes for patients in the hospital [10]. Structural characteristics, such as those that comprise a professional practice environment for nurses, are hypothesized to facilitate nursing process. These favorable practice environments have been linked to improved patient outcomes [11-13]. The purpose of this study is to examine the structure-process link: structural characteristics of hospital patient care units and the process of staff nurse care coordination. The specific aim of this study is to explore the association between the nurses'perceived professional practice environment and the impact of antecedents to that practice environment, on the activities of staff nurse care coordination as perceived by registered nurses on acute care medical-surgical units. This is a descriptive and cross-sectional study collecting data from staff nurses on 44 medical-surgical units caring for patients with co-existing chronic illness. This study will be conducted at five metro-Atlanta area hospitals. Three surveys: the practice environment scale (PES-NWI), the nurse care coordination Inventory (NCCI) and a relational coordination instrument (RCI) will be distributed. Scores from these surveys, all supported for use at the patient care unit level, will be aggregated to a unit measure [14-16]. All data will be tested for reliability and validity at the individual as well as unit level. Regression analysis will be run to describe the impact of the work environment characteristics on the process of staff nurse care coordination. The impact of higher level structural attributes on the practice environment and staff nurse care coordination will also be explored.